Journal articles: 'Space fleet'

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Balac, Milos, Sebastian Hörl, and Kay W. Axhausen. "Fleet Sizing for Pooled (Automated) Vehicle Fleets." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 9 (July 1, 2020): 168–76. http://dx.doi.org/10.1177/0361198120927388.

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This paper proposes an (automated) on-demand public transport service using different vehicle capacities to serve current car demand in cities. The service relies on space and time aggregation of passengers that have similar origins and destinations. It provides a point-to-point service with predefined pick-up and drop-off locations. In this way, detours to pick-up en-route passengers is avoided. The optimization problem that minimizes the fleet size along with limiting rebalancing distances is defined as a mixed-integer linear programming problem. Solving the problem for Zurich, Switzerland, yields, in the best case, a fleet size equal to 3.7% of the current fleet that could serve current car demand. Vehicle kilometers traveled could also be reduced by nearly 10%. Results also show that the speed of automated vehicles has a substantial effect on the necessary fleet size and free-flow speeds generally produce over-optimistic results.

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Ulrich, Clara, Bo Sølgaard Andersen, Per J. Sparre, and J. Rasmus Nielsen. "TEMAS: fleet-based bio-economic simulation software to evaluate management strategies accounting for fleet behaviour." ICES Journal of Marine Science 64, no. 4 (May 1, 2007): 647–51. http://dx.doi.org/10.1093/icesjms/fsm044.

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Abstract Ulrich, C., Andersen, B. S., Sparre, P. J., and Nielsen, J. R. 2007. TEMAS: fleet-based bio-economic simulation software to evaluate management strategies accounting for fleet behaviour. – ICES Journal of Marine Science, 64: 647–651. TEMAS (technical management measures) is a fleet-based bio-economic software for evaluating management strategies accounting for technical measures and fleet behaviour. It focuses on mixed fisheries in which several fleets can choose among several fishing activities to target different stocks in one or several areas. The software combines a management strategy evaluation framework, using a forward-running operating model and a management procedure with a fleet behaviour module simulating both short-term (effort allocation) and long-term (entry/exit) fleet dynamics. The suite of models behind TEMAS can be thought of as an extension of the traditional ICES forecast model. Alternative management scenarios can be compared and evaluated for their bio-economic consequences and robustness to parameter uncertainty. The software is generic and user-friendly, and can be run at several space and time scales.

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Ruch, Claudio, Roman Ehrler, Sebastian Hörl, Milos Balac, and Emilio Frazzoli. "Simulation-Based Assessment of Parking Constraints for Automated Mobility on Demand: A Case Study of Zurich." Vehicles 3, no. 2 (June 1, 2021): 272–86. http://dx.doi.org/10.3390/vehicles3020017.

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In a coordinated mobility-on-demand system, a fleet of vehicles is controlled by a central unit and serves transportation requests in an on-demand fashion. An emerging field of research aims at finding the best way to operate these systems given certain targets, e.g., customer service level or the minimization of fleet distance. In this work, we introduce a new element of fleet operation: the assignment of idle vehicles to a limited set of parking spots. We present two different parking operating policies governing this process and then evaluate them individually and together on different parking space distributions. We show that even for a highly restricted number of available parking spaces, the system can perform quite well, even though the total fleet distance is increased by 20% and waiting time by 10%. With only one parking space available per vehicle, the waiting times can be reduced by 30% with 20% increase in total fleet distance. Our findings suggest that increasing the parking capacity beyond one parking space per vehicle does not bring additional benefits. Finally, we also highlight possible directions for future research such as to find the best distribution of parking spaces for a given mobility-on-demand system and city.

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Ma, Changxi, Jibiao Zhou, Xuecai (Daniel) Xu, Fuquan Pan, and Jin Xu. "Fleet Scheduling Optimization of Hazardous Materials Transportation: A Literature Review." Journal of Advanced Transportation 2020 (January 20, 2020): 1–16. http://dx.doi.org/10.1155/2020/4079617.

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To comprehensively understand the research progress of the fleet scheduling for hazardous materials, the study has summarized the corresponding research results from three aspects (a) hazardous materials transportation risk, (b) route optimization, and (c) fleet scheduling, and then pointed out potential problems from six aspects: (a) the coupling risk of the transport fleet; (b) the screening of time and space for the transport of hazardous materials; (c) the scheduling optimization for transport fleets; (d) taking insufficient account of transport risks fairness; (e) insufficient robustness of scheduling schemes; and (f) lacking of research results on fleet scheduling of transport in the context of antiterrorism. After that, by considering the existing shortcomings of the current research, five research directions are presented that should be further explored in the future. Subsequently, both rough set and association rule theory is applied to explore the cause chain of transportation accidents for hazardous materials, and analyze the mechanism of transport accident for hazardous materials. Next, the Bayesian network is presented to predict the accident rate of hazardous materials transportation under different temporal and spatial conditions, and the dynamic rolling scheduling method of hazardous materials transport fleet is constructed under normal and antiterrorism background.

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Neal, Valerie. "Space policy and the size of the space shuttle fleet." Space Policy 20, no. 3 (August 2004): 157–69. http://dx.doi.org/10.1016/j.spacepol.2004.06.001.

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Fletcher-Jones, Clifford. "In Favour of an Independent Royal Space Fleet." RUSI Journal 169, no. 1-2 (February 23, 2024): 22–32. http://dx.doi.org/10.1080/03071847.2024.2359405.

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Gomez, Sebastian, Edo Berger, Peter K. Blanchard, Griffin Hosseinzadeh, Matt Nicholl, Daichi Hiramatsu, V. Ashley Villar, and Yao Yin. "The First Two Years of FLEET: An Active Search for Superluminous Supernovae." Astrophysical Journal 949, no. 2 (June 1, 2023): 114. http://dx.doi.org/10.3847/1538-4357/acc536.

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Abstract In 2019 November, we began operating Finding Luminous and Exotic Extragalactic Transients (FLEET), a machine-learning algorithm designed to photometrically identify Type I superluminous supernovae (SLSNe) in transient alert streams. Through this observational campaign, we spectroscopically classified 21 of the 50 SLSNe identified worldwide between 2019 November and 2022 January. Based on our original algorithm, we anticipated that FLEET would achieve a purity of about 50% for transients with a probability of being an SLSN, P(SLSN-I) > 0.5; the true on-sky purity we obtained is closer to 80%. Similarly, we anticipated FLEET could reach a completeness of about 30%, and we indeed measure an upper limit on the completeness of ≲33%. Here we present FLEET 2.0, an updated version of FLEET trained on 4780 transients (almost three times more than FLEET 1.0). FLEET 2.0 has a similar predicted purity to FLEET 1.0 but outperforms FLEET 1.0 in terms of completeness, which is now closer to ≈40% for transients with P(SLSN-I) > 0.5. Additionally, we explore the possible systematics that might arise from the use of FLEET for target selection. We find that the population of SLSNe recovered by FLEET is mostly indistinguishable from the overall SLSN population in terms of physical and most observational parameters. We provide FLEET as an open source package on GitHub: https://github.com/gmzsebastian/FLEET.

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Gomez, Sebastian, V. Ashley Villar, Edo Berger, Suvi Gezari, Sjoert van Velzen, Matt Nicholl, Peter K. Blanchard, and Kate D. Alexander. "Identifying Tidal Disruption Events with an Expansion of the FLEET Machine-learning Algorithm." Astrophysical Journal 949, no. 2 (June 1, 2023): 113. http://dx.doi.org/10.3847/1538-4357/acc535.

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Abstract We present an expansion of FLEET, a machine-learning algorithm optimized to select transients that are most likely tidal disruption events (TDEs). FLEET is based on a random forest algorithm trained on both the light curves and host galaxy information of 4779 spectroscopically classified transients. We find that for transients with a probability of being a TDE, P(TDE) > 0.5, we can successfully recover TDEs with ≈40% completeness and ≈30% purity when using their first 20 days of photometry or a similar completeness and ≈50% purity when including 40 days of photometry, an improvement of almost 2 orders of magnitude compared to random selection. Alternatively, we can recover TDEs with a maximum purity of ≈80% and a completeness of ≈30% when considering only transients with P(TDE) > 0.8. We explore the use of FLEET for future time-domain surveys such as the Legacy Survey of Space and Time on the Vera C. Rubin Observatory (Rubin) and the Nancy Grace Roman Space Telescope (Roman). We estimate that ∼104 well-observed TDEs could be discovered every year by Rubin and ∼200 TDEs by Roman. Finally, we run FLEET on the TDEs from our Rubin survey simulation and find that we can recover ∼30% of them at redshift z < 0.5 with P(TDE) > 0.5, or ∼3000 TDEs yr–1 that FLEET could uncover from the Rubin stream. We have demonstrated that we will be able to run FLEET on Rubin photometry as soon as this survey begins. FLEET is provided as an open source package on GitHub: https://github.com/gmzsebastian/FLEET.

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Mansouri, Masoumeh, Henrik Andreasson, and Federico Pecora. "HYBRID REASONING FOR MULTI-ROBOT DRILL PLANNING IN OPEN-PIT MINES." Acta Polytechnica 56, no. 1 (February 29, 2016): 47. http://dx.doi.org/10.14311/app.2016.56.0047.

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Fleet automation often involves solving several strongly correlated sub-problems, including task allocation, motion planning, and coordination. Solutions need to account for very specific, domaindependent constraints. In addition, several aspects of the overall fleet management problem become known only online. We propose a method for solving the fleet-management problem grounded on a heuristically-guided search in the space of mutually feasible solutions to sub-problems. We focus on a mining application which requires online contingency handling and accommodating many domainspecific constraints. As contingencies occur, efficient reasoning is performed to adjust the plan online for the entire fleet.

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Sirina, Nina Fridrikhovna, and Vadim Borisovich Sverdlov. "The model of the formation of intra-corporate relational interactions of JSC «RZD» in the sphere of the car fleet preservation." Transport of the Urals, no. 4 (2023): 17–24. http://dx.doi.org/10.20291/1815-9400-2023-4-17-24.

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The intra-corporate relational space of JSC «RZD» in the sphere of the car fleet preservation is considered. The formed commercial and production ties between the participants of the relational process within the RZD Holding are shown and analyzed. Contradictions between the participants of the inner relational space are analyzed. There are suggested solutions which simplify the procedure of the control by the departments not included into the Directorate of the infrastructure for the car fleet preservation and provide the compliance of the requirements set by the legal documentations of JSC «RZD» and the railways. It is shown that relational interactions let reduce the acuity of inconsistencies between the tasks of each department of JSC «RZD» and the management decisions directed to the control of the car fleet preservation.

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Gong, Bowen, Ruixin Wei, Dayong Wu, and Ciyun Lin. "Fleet Management for HDVs and CAVs on Highway in Dense Fog Environment." Journal of Advanced Transportation 2020 (August 14, 2020): 1–21. http://dx.doi.org/10.1155/2020/8842730.

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Adverse weather conditions have a significant impairment on the safety, mobility, and efficiency of highway networks. Dense fog is considered the most dangerous within the adverse weather conditions. As to improve the traffic flow throughput and driving safety in dense fog weather condition on highway, this paper uses a mathematical modeling method to study and control the fleet mixed with human-driven vehicles (HDVs) and connected automatic vehicles (CAVs) in dense fog environment on highway based on distributed model predictive control algorithm (DMPC), along with considering the car-following behavior of HDVs driver based on cellular automatic (CA) model. It aims to provide a feasible solution for controlling the mixed flow of HDVs and CAVs more safely, accurately, and stably and then potentially to improve the mobility and efficiency of highway networks in adverse weather conditions, especially in dense fog environment. This paper explores the modeling framework of the fleet management for HDVs and CAVs, including the state space model of CAVs, the car-following model of HDVs, distributed model predictive control for the fleet, and the fleet stability analysis. The state space model is proposed to identify the status of the feet in the global state. The car-following model is proposed to simulate the driver behavior in the fleet in local. The DMPC-based model is proposed to optimize rolling of the fleet. Finally, this paper used the Lyapunov stability principle to analyze and prove the stability of the fleet in dense fog environment. Finally, numerical experiments were performed in MATLAB to verify the effectiveness of the proposed model. The results showed that the proposed fleet control model has the ability of local asymptotic stability and global nonstrict string stability.

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12

Kosenko, K. A. "Comparative characteristic of manifestations of pathological anxiety in workers of the marine merchant and passenger fleets." Archives of psychiatry 25, no. 3 (September 18, 2019): 168–72. http://dx.doi.org/10.37822/2410-7484.2019.25.3.168-172.

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Background. The activities of seafarers are extremely complex and at the same time risky professions; they put forward specific requirements for the crew of ships. Long seagoing are associated with the constant presence of crew members in a confined space, monotony of activity, a sharp narrowing of external social relations, an increased risk of emergency situations and etc. Scientific studies show the differentiation of the negative impact of occupational stress factors depending on the ranks of long-distance sailors. Objective – to study the specifics of manifestations of anxiety reaction of workers of the marine merchant and passenger fleets to determine the need to create specific systemic measures to protect mental health for this contingent. Materials and methods. During 2016–2019 we examined 120 workers of the Ukrainian navy. Of these, 90 were sailors, minders, and other merchant fleet workers, and 30 were passenger fleet workers. All examined were men, citizens of Ukraine. The study included the use of clinical, psychopathological, psychodiagnostic and statistical methods. Results. A significant part of the deck ratings (workers) of both merchant and passenger fleets has manifestations of a pathological anxiety reaction, mainly of medium-low intensity. Representatives of the working professions of the passenger navy are characterized by more intense manifestations of anxiety symptoms, the average severity of which approaches the upper limit of subclinical values, while among the representatives of the merchant fleet it approaches the upper limit of normative indicators. Conclusions. The data obtained should be taken into account when developing specific measures of psychotherapy and psychoprophylaxis for this contingent, which is the prospect of this study.

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Zhou, Shijie, André E. Punt, Roy Deng, and Janet Bishop. "Estimating multifleet catchability coefficients and natural mortality from fishery catch and effort data: comparison of Bayesian state–space and observation error models." Canadian Journal of Fisheries and Aquatic Sciences 68, no. 7 (July 2011): 1171–81. http://dx.doi.org/10.1139/f2011-052.

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Catchability and natural mortality are key quantities in fisheries stock assessment. However, it is difficult to estimate these two parameters simultaneously using only fishery catch and effort data. A Bayesian state–space modified delay–difference model is outlined that can estimate time series of catchability by fleet as well as natural mortality. This model, and three variants thereof, is fitted to data for grooved tiger prawns ( Penaeus semisulcatus ) in Australia’s Northern Prawn Fishery during the period of the year when there is little recruitment. A model that allows for both observation and process error and estimates natural mortality is best, in terms of model selection criteria as well as fit diagnostics. The posterior median estimate for catchability for the primary target fleet ranges from 6.15 × 10−4 to 1.09 × 10−4 during 1980–2007, while the posterior median estimate for catchability for a fleet with P. semisulcatus as its byproduct is about 20% of that for the primary fleet. Fishing efficiency increased at approximately 2% annually during 1980–2007, while the weekly natural mortality is estimated to be 0.053 week–1.

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Karana, Sjafril. "Penanganan Kendaraan Bermotor Pada Kapal Angkutan Penyeberangan." Warta Penelitian Perhubungan 22, no. 3 (March 31, 2010): 287–303. http://dx.doi.org/10.25104/warlit.v22i3.1076.

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Freight fernJ fleet has an important roe in launching the economic wheel. For that reason, the level of.ship safety would need to be nuzintnined. But in recent years are still often the case calamihJ befallingthe fernJ fleet. In accordance with kind of descripti'ue, this study prauides a clearer picture about thehandling of motor vehicle in the fleet of fernJ transport. Prinuzn1 dntn and infomuztian obtained underdirect obseniation to the boot fernJ transport.Tiiere are Parious factors thnt become the azuse of tlze accident or fire on board of the fernJ transport,including handling of ziehicles that are transported on the ship does not comply with regulations. It isslumm that the placement of motor ziehicles an fern/s deck is not yet unorganized. Space around theramp door location should be clear, but it was still loaded with drums, tliere is also a ramp door thatshould be tight closed, but now it was still slumm space wide enoughTiiere fore, to en[umce the safety of ships in their operation, niles enforcement needs to be appliedstrictly, it's tinie to apply las/zing system on each fem; in any condition. In addition, to ensure tlieenforcement of mies, supennsian needs to be clone on a regulnr basis and application of severe sanctionsis one of tlie effort tluit need to be applied, eitlier before tlie process of loading a vehicle or at tlietinie of sailing ships. So that any incident tluit occurs primarily in tlie space of vehicle ca:n be detectedas early as -possible.Keywords : zielzicle handling - safety of ferry fleet

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Silva, Dahlen, Dávid Földes, and Csaba Csiszár. "Autonomous Vehicle Use and Urban Space Transformation: A Scenario Building and Analysing Method." Sustainability 13, no. 6 (March 10, 2021): 3008. http://dx.doi.org/10.3390/su13063008.

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The use of autonomous vehicles (AVs) has the potential to transform users’ behaviour and urban space management. Quantitative and qualitative analyses of impacts require a scenario building method. We considered the fleet size, modal share, car ownership, parking preferences, and urban space repurposing during the elaboration of a novel method. Existing scenarios and results of a questionnaire survey have been used as sources. The method was applied to build scenarios in a case study in Budapest, Hungary. The results were used to calculate the impacts on urban space management, including environmental savings. The key findings are: scenarios with significant shared AV use show that parking demand may be minimised (almost 83%) and urban space repurposing has the highest potential; furthermore, AV use and sharing acceptability may decrease the fleet size and alter the type of shared mode to multiple occupancies. The developed scenario building method serves as a base for future studies. The produced scenarios allow the researchers to focus on the analysis of the impacts caused.

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Krause, Robert B. "United States Launch Vehicle Systems." International Astronomical Union Colloquium 123 (1990): 325–32. http://dx.doi.org/10.1017/s025292110007723x.

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AbstractUnited States policy for national space launch capability provides for a balanced mix of launches, utilizing the Space Shuttle and Expendable Launch Vehicles (ELVs). It also directs government agencies to encourage and support the development of a domestic commercial expendable launch vehicle industry. This is to be accomplished by contracting for necessary ELV launch services directly from the private sector and by facilitating access by commercial launch firms to national launch and launch-related property and services they request to support these commercial operations.The current mixed fleet includes the Space Shuttle and four expendable launch vehicles - Titan, Atlas, Delta and Scout. New small class launch vehicles, including Pegasus, are in development. In addition, studies are underway to assure that the United States has cost-effective, reliable access to space, heavy-lift launch capability, and a new manned spacecraft after the current Space Shuttle reaches the end of its operational life. This paper will highlight the current capabilities of the mixed fleet and summarize the plans for new or modified United States launch vehicles through the first decade of the next century.

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Chervenchuk, V. D., G. V. Redreev, I. V. Chervenchuk, A. V. Shimokhin, and A. A. Luchinovich. "Information and search space for monitoring the machine and tractor fleet." IOP Conference Series: Materials Science and Engineering 941 (December 25, 2020): 012049. http://dx.doi.org/10.1088/1757-899x/941/1/012049.

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Dumas, Juliette. "Ebru Boyar & Kate Fleet (eds), Ottoman Women in Public Space." Clio, no. 48 (December 1, 2018): 289–92. http://dx.doi.org/10.4000/clio.15347.

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Neal, Valerie. "Bumped from the shuttle fleet: Why didn't Enterprise fly in space?" History and Technology 18, no. 3 (January 2002): 181–202. http://dx.doi.org/10.1080/0734151022000034134.

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Kristjanpoller, Fredy, Kevin Michell, Werner Kristjanpoller, and Adolfo Crespo. "Fleet optimization considering overcapacity and load sharing restrictions using genetic algorithms and ant colony optimization." Artificial Intelligence for Engineering Design, Analysis and Manufacturing 34, no. 1 (January 13, 2020): 104–13. http://dx.doi.org/10.1017/s0890060419000428.

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AbstractThis paper presents a fleet model explained through a complex configuration of load sharing that considers overcapacity and is based on a life cycle cost (LCC) approach for cost-related decision-making. By analyzing the variables needed to optimize the fleet size, which must be evaluated in combination with the event space method (ESM), the solution to this problem would normally require high computing performance and long computing times. Considering this, the combined use of an integer genetic algorithm (GA) and the ant colony optimization (ACO) method was proposed in order to determine the optimal solution. In order to analyze and highlight the added value of this proposal, several empirical simulations were performed. The results showed the potential strengths of the proposal related to its flexibility and capacity in solving large problems with a near optimal solution for large fleet size and potential real-world applications. Even larger problems can be solved this way than by using the complete enumeration approach and a non-family fleet approach. Thus, this allows for a more real solution to fleet design that also considers overcapacity, availability, and an LCC approach. The simulations showed that the model can be solved in much less time compared with the base model and allows for the resolution of a fleet of at least 64 trucks using GA and 130 using ACO, respectively. Thus, the proposed framework can solve real-world problems, such as the fleet design of mining companies, by offering a more realistic approach.

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Kazmina, Olesya A., Sergei A. Kazmin, Nadezhda Y. Pyshkina, and Anna A. Kholopova. "A conceptual approach to the creation of an information system of industry analytics for the fleet." Russian Journal of Water Transport, no. 74 (March 20, 2023): 117–29. http://dx.doi.org/10.37890/jwt.vi74.312.

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The article presents a description of the concept of creating an information system for industry analytics for the fleet. The system was developed on the basis of the analytical platform QlikView. The purpose of creating an information system of industry analytics for the fleet is the operational preparation of analytics on fleet indicators in the required sections based on the analysis of large amounts of data in a single space. The need to create such a system is associated with the need for operational management decision-making based on a variety of analytics and regular monitoring of industry indicators, which is associated with time-consuming processing and analysis of large amounts of data, visualization of indicators in the required sections. The use of the developed system will optimize the current business processes of enterprises of the industry at any level.

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Kim, Junghyun. "Building a Space Fleet: The Trace of the Maritime Age and the Age of Space Battlefield." Journal of the KNST 6, no. 1 (March 31, 2023): 9–18. http://dx.doi.org/10.31818/jknst.2023.03.6.1.9.

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Wang, Yu, Kaibo Yuan, Mengyuan Zhu, and Shuijin Li. "A Time-and-Space-Network-Based Green Fleet Planning Model and Its Application for a Hub-and-Spoke Network." Sustainability 15, no. 7 (March 28, 2023): 5832. http://dx.doi.org/10.3390/su15075832.

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Most previous studies on airline fleet planning have focused solely on economic considerations, neglecting the impact of carbon reduction. This paper presents a novel method for green fleet planning, using a bi-level programming model to balance conflicts among stakeholders while considering uncertain parameters such as demand and operating costs. The upper model aims to reduce carbon emissions by taking into account government constraints, such as carbon allowances and carbon prices, as well as airline satisfaction. The lower model seeks to maximize airline revenue using a space-and-time network model based on given airline flight schedules. To verify the game model, a case study utilizing randomly generated scenarios is employed within the context of China’s aviation-specific emissions trading scheme. Results show that: (1) compared to the scenario without a policy aiming at reducing carbon emissions, this method reduces carbon emissions by 23.03% at the expense of a 6.96% reduction in terms of the airline’s operating profit; (2) when passenger demand levels increase to 160%, the profitability of the proposed fleet increases by 50.83%, while there were only insignificant changes in carbon emissions; (3) the proposed methodology can assist the airlines systematically to reduce carbon emissions and provide valuable strategic guidance for policy makers.

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Sirina, Nina Fridrikhovna, and Vadim Borisovich Sverdlov. "Relational strategy of car fleet safety assurance." Transport of the Urals, no. 3 (2022): 22–27. http://dx.doi.org/10.20291/1815-9400-2022-3-22-27.

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The paper considers development of car services after reformation of railway transport and creation of the JSC «RZD». The authors have presented and analysed commercial and production connections between participants of transportation process. They have revealed contradictions between participants of transportation process leading to conflicts that need solutions. It is noticed that for balancing of conflicts it is necessary to approach on the basis of the use of the accumulated scientific experience on organization of interaction of the car-repair complex with external environment. As a result, the authors suggest solving a task of balancing the JSC «RZD» conflicts with external environment with the use of relation strategy. They have developed a capital-centric model of the JSC «RZD» relation space with regard to safety of car fleet and have determined main directions for creating a relation strategy of the JSC «RZD» in car services.

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Ghalehkhondabi, Iman, and Dale T. Masel. "Storage allocation in a warehouse based on the forklifts fleet availability." Journal of Algorithms & Computational Technology 12, no. 2 (April 4, 2018): 127–35. http://dx.doi.org/10.1177/1748301818761130.

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Product allocation is one of the most important duties in warehousing operations. Based on the time and the number of products to put away and retrieve, storage allocation can directly affect the efficiency of a warehouse in terms of both response and operation time. Traditionally, the product storage allocation is done based on the less distance of shipment but focusing on distance may decrease the efficiency of a warehouse in terms of efficient utilization of resources such as warehouse inbound shipping fleet. This paper proposes a storage space allocation model that considers the availability of forklift fleet in a warehouse instead of product shipping distance. The numerical example shows that storing the products based on the proposed model can reduce the volume of forklift fleet idle hours on days with fewer volume of receiving and shipping outs. The proposed model also reduces the overtime working hours on days with higher volume of receiving and shipping out products.

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Bukljaš, Mihaela, Kristijan Rogić, and Vladimir Jerebić. "Distributionally Robust Model and Metaheuristic Frame for Liner Ships Fleet Deployment." Sustainability 14, no. 9 (May 5, 2022): 5551. http://dx.doi.org/10.3390/su14095551.

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The container shipping industry market is very dynamic and demanding, economically, politically, legally, and financially. Considering the high cost of core assets, ever rising operating costs, and the volatility of demand and supply of cargo space, the result is an industry under enormous pressure to remain profitable and competitive. To maximize profits while maintaining service levels and ensuring the smooth flow of cargo, it is essential to make strategic decisions in a timely and optimal manner. Fleet deployment selection, which includes the profile of vessel hire, as well as their capacity and port rotation, is one of the most important strategic and tactical decisions container shipping operators must make. Bearing in mind that maritime business is inherently stochastic and uncertain, the key aims of this paper are to address the problem of fleet deployment under uncertain operating conditions, and to provide an integrated and optimized tool in the form of a mathematical model, metaheuristic algorithm, and computer program. Furthermore, this paper will show that the properties of the provided solutions exceed those offered in the literature so far. Such a solution will provide the shipping operator with a decision tool to best deploy its fleet in a way that responds more closely to real life situations and to meet the maximum demand for cargo space with minimal expense. The final goal is to minimize the operating costs while managing cargo flows and reducing the risks of unfulfilled customer demands.

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Holt, S. S. "The Next Generation of High-energy Astrophysics Observatories." Symposium - International Astronomical Union 195 (2000): 5–13. http://dx.doi.org/10.1017/s0074180900162734.

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The sky will soon be populated with a fleet of new X- and gamma-ray satellites with extraordinary capabilities. This paper is meant to introduce these new missions, Chandra, XMM, and Astro-E, which will provide a large fraction of our high energy “space observatory” functionality for the next decade.

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Kokosalakis, Yiannis. "Building a Red Navy: Communist Activism and Military Authority in the Baltic Fleet, 1918–1940." Contemporary European History 31, no. 2 (December 14, 2021): 214–26. http://dx.doi.org/10.1017/s0960777321000126.

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This article examines the activities of the Soviet military-political organs in the Baltic Fleet. It shows that the web of party institutions transformed the fleet into a space of political and social activism that had little to do with the strictly military aspects of government policy. Such activism was nevertheless unfailingly promoted, even as it became clear that it compromised core elements of military efficiency such as discipline and well-defined chains of command. This argument has implications for our broader understanding of the nature of the Soviet state. It indicates that once the Bolsheviks’ revolutionary ideology had become institutionalised in the state via the ubiquitous presence of party organs, pragmatic retreats for organisational efficiency became exceptionally difficult to implement.

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Soilleux, Richard, Stephen Baxter, Michel Lamontagne, and Robert Freeland. "The Settlement of Space: Economical and Logistical Drivers and Constraints." Journal of the British Interplanetary Society 76, no. 5 (July 12, 2023): 154–62. http://dx.doi.org/10.59332/jbis-076-05-154.

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This work is part of the BIS SPACE technical project studying long term possibilities for an expansion of industrial civilisation on Earth and in space. This paper traces the potential development of space settlements through four ‘generations’, driven and constrained by various economic, physical, and cultural factors. To provide a context for later work, time scales and orders of magnitudes are estimated together with constraints and drivers for space settlement. Following papers will explore the technology of fast transits within the Solar System required to support the economic model and define a fleet of interplanetary craft, based on flow stabilized Z-pinch fusion engines. Keywords: SPACE Project, In-Situ Resource Utilization, Space Settlement, Fission and Fusion Powered Spaceships, Interplanetary Logistics, Dyson Swarm, Kardashev Type I and II

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Soilleux, Richard, Stephen Baxter, and Michel Lamontagne. "The Settlement of Space: Economical and Logistical Drivers and Constraints." Journal of the British Interplanetary Society 76, no. 5 (July 12, 2023): 154–62. http://dx.doi.org/10.59332/jbis-076-05-0154.

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This work is part of the BIS SPACE technical project studying long term possibilities for an expansion of industrial civilisation on Earth and in space. This paper traces the potential development of space settlements through four ‘generations’, driven and constrained by various economic, physical, and cultural factors. To provide a context for later work, time scales and orders of magnitudes are estimated together with constraints and drivers for space settlement. Following papers will explore the technology of fast transits within the Solar System required to support the economic model and define a fleet of interplanetary craft, based on flow stabilized Z-pinch fusion engines. Keywords: SPACE Project, In-Situ Resource Utilization, Space Settlement, Fission and Fusion Powered Spaceships, Interplanetary Logistics, Dyson Swarm, Kardashev Type I and II

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Sennefelder, Roman Michael, Rubén Martín-Clemente, and Ramón González-Carvajal. "Energy Consumption Prediction of Electric City Buses Using Multiple Linear Regression." Energies 16, no. 11 (May 27, 2023): 4365. http://dx.doi.org/10.3390/en16114365.

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The widespread electrification of public transportation is increasing and is a powerful way to reduce greenhouse gas (GHG) emissions. Using real-world driving data is crucial for vehicle design and efficient fleet operation. Although electric powertrains are significantly superior to conventional combustion engines in many aspects, such as efficiency, dynamics, noise or pollution and maintenance, there are several factors that still hinder the widespread penetration of e-mobility. One of the most critical points is the high costs—especially of battery electric buses (BEB) due to expensive energy storage systems. Uncertainty about energy demand in the target scenario leads to conservative design, inefficient operation and high costs. This paper is based on a real case study in the city of Seville and presents a methodology to support the transformation of public transportation systems. We investigate large real-world fleet measurement data and introduce and analyze a second-stage feature space to finally predict the vehicles’ energy demand using statistical algorithms. Achieving a prediction accuracy of more than 85%, this simple approach is a proper tool for manufacturers and fleet operators to provide tailored mobility solutions and thus affordable and sustainable public transportation.

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Ackerman, Brian M. "Modular Gas Turbine Propulsors: A Viable Alternative for Today’s Merchant Fleet." Marine Technology and SNAME News 40, no. 02 (April 1, 2003): 106–25. http://dx.doi.org/10.5957/mt1.2003.40.2.106.

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Gas turbines offer the commercial shipping industry the best power to volume ratio available for a propulsion package. When coupled with a podded propulsor, gas turbines can be placed in a module anywhere on the vessel, allowing optimal use of vessel space for cargo. As the shipping market continues to evolve, modular gas turbines seem to be the logical choice for future vessels. The object of this paper is to demonstrate the substantial increase in profits associated with a modular gas turbine propulsion package.

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Bocewicz, Grzegorz, Robert Wójcik, Zbigniew Antoni Banaszak, and Paweł Pawlewski. "Multimodal Processes Rescheduling: Cyclic Steady States Space Approach." Mathematical Problems in Engineering 2013 (2013): 1–24. http://dx.doi.org/10.1155/2013/407096.

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The paper concerns cyclic scheduling problems arising in a Multimodal Transportation Network (MTN) in which several unimodal networks (AGVs, hoists, lifts, etc.) interact with each other via common shared workstations as to provide a variety of demand-responsive material handling operations. The material handling transport modes provide movement of work-pieces between workstations along their manufacturing routes in the MTN. The goal is to provide a declarative framework enabling to state a constraint satisfaction problem aimed at AGVs fleet match-up scheduling taking into consideration assumed itineraries of concurrently manufactured product types. In that context, treating the different product types as a set of cyclic multimodal processes is the main objective to discuss the conditions sufficient for FMS rescheduling imposed by production orders changes. To conclude, the conditions sufficient for an FMS rescheduling imposed by changes of production orders treated as cyclic multimodal processes are stated as the paper’s main contribution.

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Wu, Peiling, and Joseph C. Hartman. "Case Study: Solving a Rental Fleet Sizing Model with a Large Time–Space Network." Engineering Economist 55, no. 1 (February 26, 2010): 71–104. http://dx.doi.org/10.1080/00137910903577803.

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Miksa, Wojciech Jerzy, and Tomasz Goetzendorf-Grabowski. "Partially feasible solution space for integrated SATS operations." Aircraft Engineering and Aerospace Technology 91, no. 3 (March 4, 2019): 448–56. http://dx.doi.org/10.1108/aeat-01-2018-0045.

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Purpose The purpose of this paper is to investigate the feasibility of solving an integrated flight scheduling, fleet assignment and crew pairing problem for an on-demand service using a small, up to 19-seater, aircraft. Design/methodology/approach Evolutionary algorithm is developed to solve the problem. Algorithm design assumes indirect solution representation that allows to evaluate partially feasible solutions only and speed up calculations. Tested algorithm implementation takes advantage of the graphic processing unit. Findings Performed tests confirm that the algorithm can successfully solve the defined integrated scheduling problem. Practical implications The presented algorithm allows to optimise on-demand transport service operation within minutes. Social implications Optimisation of operation cost contributes to better accessibility of transport. Originality/value The presented integrated formulation allows to avoid sub optimal solutions that are results of solving sequential sub problems. Indirect representation and evaluation strategy can be applied to speed up calculations in other problems as well.

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Łukasiewicz, Jerzy, Joanna Lubieniecka, Jerzy Kusiński, Wiesław Sarna, and Krzysztof Tchórznicki. "The Automated System of Optical Observation and Tracking of Space Objects." Journal of KONBiN 50, no. 1 (March 1, 2020): 237–58. http://dx.doi.org/10.2478/jok-2020-0014.

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AbstractHaving a fleet of artificial satellites necessitates the construction of a system that will enable obtaining information on the situation in the Earth orbit (Space Situation Awareness - SSA). Such systems are built either as active radar systems or as passive optical systems. The automated system of optical observation and tracking of space objects (ASOPEK) consists of two optical systems (wide-angle and narrow-angle) and software enabling: detection of artificial satellites in the field of view of the system, identification of detected objects, updating the satellite database with unknown objects, updating orbits of observed objects. The ASOPEK system was created as part of a project financed by the National Center for Research and Development No. DOB-BIO7/25/02/2015.

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Dicht, Burton. "Shuttle diplomacy." Mechanical Engineering 133, no. 07 (July 1, 2011): 46–53. http://dx.doi.org/10.1115/1.2011-jul-4.

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This article analyzes the decisions and technological challenges that drove the Space Shuttle’s development. The goal of the Shuttle program was to create a reusable vehicle that could reduce the cost of delivering humans and large payloads into space. Although the Shuttle was a remarkable flying machine, it never lived up to the goals of an airline-style operation with low operating costs. In January 2004, a year after the Columbia accident, President George W. Bush unveiled the “Vision for U.S. Space Exploration” to guide the U.S. space effort for the next two decades. A major component of the new vision, driven by the recommendations of the Columbia Accident Investigation Board, was to retire the Space Shuttle fleet as soon as the International Space Station assembly was completed. With cancellation of the Constellation program in 2010, the planned successor to the Shuttle, the U.S. space program is now in an era of uncertainty.

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ARTYMYSHYN, Pavlo. "KHARKIV AGREEMENTS OF 2010: VISIONS OF POLITICAL, MEDIA AND EXPERT CIRCLES IN UKRAINE." Ukraine: Cultural Heritage, National Identity, Statehood 33 (2020): 194–213. http://dx.doi.org/10.33402/ukr.2020-33-194-213.

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The main visions of the political, media, and expert circles in Ukraine concerning the conclusion of the Kharkiv Agreements in 2010 – the pact between Ukraine and the Russian Federation on the stay of the Black Sea Fleet of the Russian Federation Navy on the territory of Ukraine are determined. It is alleged that circles close to the President of Ukraine, Viktor Yanukovych, saw them as a sign of the beginning of an era of intense Ukrainian-Russian relations, including the issue of cheaper gas, which would help to overcome the crisis in the economy and provide a lower price for gas for both industrial and household consumers. Instead, the agreements in the opposition were seen as a betrayal of Ukrainian national interests, the creation in the Black Sea region of a destabilizing center in the form of the Black Sea Fleet of the Russian Navy, and the beginning of Ukraine’s integration into the Russian geopolitical space. At the same time, the Ukrainian side was unable to persuade the Russian to sign new gas agreements to revise the price of «blue fuel» in essence, rather than through a discount system. Opposition criticism was also not effective under these circumstances: although the topic of prolongation of the Russian Navy’s Black Sea Fleet base in Sevastopol became one of the tenets of their anti-government rhetoric, however, the unification of the opposition had not yet grown into an institutionalized movement, acquiring such features only on the eve of the parliamentary elections in 2012. Instead, the Russian side took full advantage of the Ukrainian concessions of 2010. It is the preservation of the Black Sea Fleet on the Crimean Peninsula that allowed the Russians to prepare the ground for its annexation and for the nourishment of the Russian chauvinist ideology about Sevastopol as a «Russian city». Keywords: Kharkiv Agreements of 2010, politicum, mass media, expert environment, visions, the Black Sea Fleet of the Russian Federation Navy, gas, Ukraine, Russian Federation.

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Garretson, Lieutenant Colonel Peter. "Viewpoint: The Next Great White Fleet: Extending the Benefits of the International System into Space." Astropolitics 6, no. 1 (March 4, 2008): 50–70. http://dx.doi.org/10.1080/14777620801921419.

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Sherali, Hanif D., and Cihan H. Tuncbilek. "Static and Dynamic Time-Space Strategic Models and Algorithms for Multilevel Rail-Car Fleet Management." Management Science 43, no. 2 (February 1997): 235–50. http://dx.doi.org/10.1287/mnsc.43.2.235.

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Siswantoro, Nurhadi, Hari Prastowo, Hafiz Rahadyan Nugroho, Muhammad Badrus Zaman, Trika Pitana, Dwi Priyanta, and Hari Prastowo. "A Preliminary Web-Based Intermediary Application Design For Ship Repair Planning Services." IOP Conference Series: Earth and Environmental Science 1081, no. 1 (September 1, 2022): 012047. http://dx.doi.org/10.1088/1755-1315/1081/1/012047.

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Abstract According to data from the 2019 Ministry of Transportation Statistics Book, the number of national shipping fleets or ships in the country from 2015-2019 has doubled. However, from the potential of the current operating fleet, it shows that more than 75% of the fleet are over 20 years old. With such conditions, it is necessary to plan for ship maintenance and repairs to be as good as possible and to spend as little time as possible. This research aims to design a web-based intermediary application for ship repair planning services that can be accessed by using a website browser. The initial stage is to observe the condition of ship repair and planning from shipyard and shipowner perspectives through the literature and field study. From the result of the observation, then analyze what problems occur in the field and then arrange what functions or features are needed to be included in the design of the application to be able to solve these problems. Application design is done by making mock-ups, designing interfaces, creating databases and coding of the application system. After that, the application is tested and verified to find out that the application can run as intended and know the strengths and weaknesses of the application. The features in this application are designed to intermediary shipyard and shipowner in the ship repair planning process. The result of this preliminary web-based application design is by using this application, ship owners can search for docking space in available shipyards according to the schedule and place desired by the shipowner. In addition, by using this application, the shipowner can find out when the ship’s certificate expires so that they can prepare a schedule for conducting a survey. Then, both the shipyard and the shipowner can use this application to monitor and report on the progress of ship repair work.

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Tsgoev, Taimuraz Fedorovich, and Valery Borisovich Ambalov. "IMPACT OF THE STATE OF TRANSPORT INFRASTRUCTURE ON THE ECOLOGY OF VLADIKAVKAZ." EurasianUnionScientists 5, no. 8(77) (September 16, 2020): 39–44. http://dx.doi.org/10.31618/esu.2413-9335.2020.5.77.991.

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Effective regulation of traffic flows within the urban area is of great importance for the cleanliness of the atmospheric air of cities and megacities. The article presents the most relevant problems related to the city's transport infrastructure, which entails both an increase in chemical emissions and physical pollution of the city's environment, primarily increased noise. Due to the growth of the automobile fleet, according to expert estimates and research conducted in Vladikavkaz, especially in its historical part, there is more than a twofold shortage of Parking spaces. The real lack of space for vehicles forces drivers to Park vehicles in clear violation of traffic Rules, which leads to a significant reduction in the capacity of streets and the occurrence of congestion. And as a result, pollution of the environment.

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CHILINGARIAN, A., V. BABAYAN, N. BOSTANJYAN, and G. KARAPETYAN. "CORRELATED MEASUREMENTS OF THE SECONDARY COSMIC RAY FLUXES BY THE NEUTRON MONITORS AND MUON TELESCOPES." International Journal of Modern Physics A 20, no. 29 (November 20, 2005): 6642–45. http://dx.doi.org/10.1142/s0217751x0502968x.

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Radiation and Geomagnetic storms, which are elements of Space Weather, are part of the major obstacles for Space Operations. Reliable forecasting of the arrival of these dangerous elements is of vital importance for the orbiting flights and electric power distribution in near polar regions. In addition to the fleet of space-born instruments, worldwide networks of particle detectors spread along different latitudes and longitudes, provide valuable information on the intensity and anisotropy of the variable cosmic ray fluxes. Aragats Space-Environmental Center provides monitoring of the different species of secondary cosmic rays at two altitudes and with different energy thresholds. 1-minute data is available on-line from URL 〈〉. We demonstrated the sensitivity of the different species of secondary cosmic ray flux to geophysical conditions, taking as examples extremely violent events of end of October – November 2003. Also we introduce the correlation analysis of the different components of registered time-series as a new tool for the classification of the geoeffective events.

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Bit-Monnot, Arthur, Rafael Bailon-Ruiz, and Simon Lacroix. "A Local Search Approach to Observation Planning with Multiple UAVs." Proceedings of the International Conference on Automated Planning and Scheduling 28 (June 15, 2018): 437–45. http://dx.doi.org/10.1609/icaps.v28i1.13924.

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Observation planning for Unmanned Aerial Vehicles (UAVs) is a challenging task as it requires planning trajectories over a large continuous space and with motion models that can not be directly encoded into current planners. Furthermore, realistic problems often require complex objective functions that complicate problem decomposition. In this paper, we propose a local search approach to plan the trajectories of a fleet of UAVs on an observation mission. The strength of the approach lies in its loose coupling with domain specific requirements such as the UAV model or the objective function that are both used as black boxes. Furthermore, the Variable Neighborhood Search (VNS) procedure considered facilitates the adaptation of the algorithm to specific requirements through the addition of new neighborhoods. We demonstrate the feasibility and convenience of the method on a large joint observation task in which a fleet of fixed-wing UAVs maps wildfires over areas of a hundred square kilometers. The approach allows generating plans over tens of minutes for a handful of UAVs in matter of seconds, even when considering very short primitive maneuvers.

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Yue, Yisong, Lavanya Marla, and Ramayya Krishnan. "An Efficient Simulation-Based Approach to Ambulance Fleet Allocation and Dynamic Redeployment." Proceedings of the AAAI Conference on Artificial Intelligence 26, no. 1 (September 20, 2021): 398–405. http://dx.doi.org/10.1609/aaai.v26i1.8176.

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We present an efficient approach to ambulance fleet allocation and dynamic redeployment, where the goal is to position an entire fleet of ambulances to base locations to maximize the service level (or utility) of the Emergency Medical Services (EMS) system. We take a simulation-based approach, where the utility of an allocation is measured by directly simulating emergency requests. In both the static and dynamic settings, this modeling approach leads to an exponentially large action space (with respect to the number of ambulances). Futhermore, the utility of any particular allocation can only be measured via a seemingly “black box” simulator. Despite this complexity, we show that embedding our simulator within a simple and efficient greedy allocation algorithm produces good solutions. We derive data-driven performance guarantees which yield small optimality gap. Given its efficiency, we can repeatedly employ this approach in real-time for dynamic repositioning. We conduct simulation experiments based on real usage data of an EMS system from a large Asian city, and demonstrate significant improvement in the system’s service levels using static allocations and redeployment policies discovered by our approach.

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Ramaroson, R., and N. Louisnard. "Potential effects on ozone of future supersonic aircraft/2D simulation." Annales Geophysicae 12, no. 10/11 (August 31, 1994): 986–95. http://dx.doi.org/10.1007/s00585-994-0986-3.

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Abstract. In a previous work, the stratospheric effect of a future supersonic aircraft fleet on ozone has been simulated, by using a photochemical diffusive 1D model and a 2D photochemical, radiative dynamical model. The fleet scenario was defined by Aerospatiale and Snecma for a current technology Mach-2 aircraft; the models were limited to simplified homogeneous phase reactions. The results indicated a global ozone decrease of about 1.5% in steady-state conditions. Now the 2D model has been upgraded and includes the classical heterogeneous reactions with Polar Stratospheric Clouds (PSC) and aerosol. It also takes into account the natural or anthopogenic evolution of the background atmosphere. The scenario has been optimized to meet more realistic conditions. Thus, new results are presented. The main conclusion concerning the calculated impact of a realistic fleet for the next 20-50 years is still weaker than in the previous work: the decrease for the total ozone would always be lower than 0.3%. These results are commented, with the help of a parametric study, pointing out the importance of the background atmosphere and especially the total chlorine loading and the aerosol surface area.

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Templ, Matthias, and Christoph Heitz. "Fleet Management in Free-Floating Bike Sharing Systems Using Predictive Modelling and Explorative Tools." Austrian Journal of Statistics 49, no. 2 (March 20, 2020): 53–69. http://dx.doi.org/10.17713/ajs.v49i2.1114.

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For redistribution and operating bikes in a free-floating systems, two measures are of highest priority. First, the information about the expected number of rentals on a day is an important measure for service providers for management and service of their fleet. The estimation of the expected number of bookings is carried out with a simple model and a more complex model based on meterological information, as the number of loans depends strongly on the current and forecasted weather. Secondly, the knowledge of a service level violation in future on a fine spatial resolution is important for redistribution of bikes. With this information, the service provider can set reward zones where service level violations will occur in the near future. To forecast a service level violation on a fine geographical resolution the current distribution of bikes as well as the time and space information of past rentals has to be taken into account. A Markov Chain Model is formulated to integrate this information. We develop a management tool that describes in an explorative way important information about past, present and predicted future counts on rentals in time and space. It integrates all estimation procedures. The management tool is running in the browser and continuously updates the information and predictions since the bike distribution over the observed area is in continous flow as well as new data are generated continuously.

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Hilborn, Ray, and Carl J. Walters. "A General Model for Simulation of Stock and Fleet Dynamics in Spatially Heterogeneous Fisheries." Canadian Journal of Fisheries and Aquatic Sciences 44, no. 7 (July 1, 1987): 1366–69. http://dx.doi.org/10.1139/f87-163.

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A simple simulation model of stock and fleet dynamics is described that allows rapid exploration of the dynamics of fisheries in a spatially heterogeneous environment. The model simulates how fishermen allocate their search effort among spatial areas in relation to differential catch rates, prices, or area-specific desirabilities. The model runs in a few seconds per simulated year on an IBM microcomputer in interpreted BASIC, although both age structure and space are explicitly represented. The importance of exploring dynamic behavior of fisheries systems is discussed.

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He, J. Y., D. H. Chen, and X. C. Liu. "Study on trajectory optimization of satellite rapid orbit formation flying for space object." Journal of Physics: Conference Series 2746, no. 1 (May 1, 2024): 012005. http://dx.doi.org/10.1088/1742-6596/2746/1/012005.

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Abstract This paper proposes a method of collaborative trajectory planning that utilizes convex optimization and IFPSO to tackle the issue of rapid formation reconstruction by multiple satellites in a low Earth circular orbit. The trajectory optimisation in this study uses convex optimisation and takes into account thrust limitations and safety distance. The time optimal solution is replaced by the path optimal solution, resulting in a suboptimal solution. The time-suboptimal trajectory solving method for formation flying using the CVX software is designed. The IFPSO is used to allocate configurations and waypoints for formation reconstruction, with the aim of balancing fuel consumption across the fleet and reducing the overall fuel consumption of the satellite. The effectiveness of the proposed approach is confirmed by numerical simulation. Despite sacrificing some computational efficiency, the method offered can solve the issues of configuration allocation and trajectory optimization.

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Wetz, Tamino, Norman Wildmann, and Frank Beyrich. "Distributed wind measurements with multiple quadrotor unmanned aerial vehicles in the atmospheric boundary layer." Atmospheric Measurement Techniques 14, no. 5 (May 26, 2021): 3795–814. http://dx.doi.org/10.5194/amt-14-3795-2021.

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Abstract. In this study, a fleet of quadrotor unmanned aerial vehicles (UAVs) is presented as a system to measure the spatial distribution of atmospheric boundary layer flow. The big advantage of this approach is that multiple and flexible measurement points in space can be sampled synchronously. The algorithm to obtain horizontal wind speed and direction is designed for hovering flight phases and is based on the principle of aerodynamic drag and the related quadrotor dynamics. During the FESST@MOL campaign at the boundary layer field site (Grenzschichtmessfeld, GM) Falkenberg of the Lindenberg Meteorological Observatory – Richard Assmann Observatory (MOL-RAO), 76 calibration and validation flights were performed. The 99 m tower equipped with cup and sonic anemometers at the site is used as the reference for the calibration of the wind measurements. The validation with an independent dataset against the tower anemometers reveals that an average accuracy of σrms<0.3 m s−1 for the wind speed and σrms,ψ<8∘ for the wind direction was achieved. Furthermore, we compare the spatial distribution of wind measurements with the fleet of quadrotors to the tower vertical profiles and Doppler wind lidar scans. We show that the observed shear in the vertical profiles matches well with the tower and the fluctuations on short timescales agree between the systems. Flow structures that appear in the time series of a line-of-sight measurement and a two-dimensional vertical scan of the lidar can be observed with the fleet of quadrotors and are even sampled with a higher resolution than the deployed lidar can provide.

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Journal articles on the topic 'Space fleet'

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